Abstract: To examine the effects of foliar application of methanol and tetrahydrofolate on yield and yield components of rice, an experiment was conducted in Water and Soil Farm of Iran’s Rice Research Institute located in the city of Rasht in the agricultural year of 2010. Accordingly, an experiment was conducted with factorial arrangement on the basis of randomized complete blocks design with three replications. The 1st agent was the concentration of methanol at 4 levels (control, 10, 20 and 30% by volume) and the 2nd agent was tetrahydrofolate at 4 levels (control, 1-3 mg L-1). The results showed that foliar application of methanol significantly affects the traits of the number of fertile tillers, total number of tillers, number of filled spikelets, number of hollow spikelets, paddy yield and thousand kernel weight at 1% level. In general, the highest values of yield and yield components were observed at concentrations of 20% (by volume) methanol and the highest number of hollow spikelets was in control. The effect of tetrahydrofolate on paddy yield and thousand kernel weight was significant at 1% probability level and the maximum averages belonged to 3 g L-1 of tetrahydrofolate.